INFORMATION ON CEREBRAL ANEURYSM

A cerebral aneurysm (also known as an intracranial or intracerebral aneurysm) is a weak or slight spot on a blood vessel in the brain that balloons out and fills with blood. The bulging aneurysm can put pressure on a nerve or surrounding brain tissue. It may also leak or rupture, spilling blood into the surrounding tissue (called a hemorrhage). Some cerebral aneurysms, chiefly those that are very small, do not bleed or cause other problems. Cerebral aneurysms can take place anywhere in the brain, but most are situated along a loop of arteries that run between the underside of the brain and the base of the skull.

CAUSES OF CEREBRAL ANEURYSM

Most cerebral aneurysms are congenital, resulting from an inborn irregularity in an artery wall. Cerebral aneurysms are also more common in people with certain inherited diseases, such as connective tissue disorders and polycystic kidney disease, and certain circulatory disorders, such as arteriovenous malformations.
Other causes include trauma or injury to the head, high blood pressure, infection, tumors, atherosclerosis (a blood vessel disease in which fats build up on the inside of artery walls) and other diseases of the vascular system, cigarette smoking, and drug abuse. Some investigators have considered that oral contraceptives may increase the risk of developing aneurysms.
Aneurysms that result from an infection in the arterial wall are called mycotic aneurysms. Cancer-related aneurysms are often associated with primary or metastatic tumors of the head and neck. Drug abuse, mainly the habitual use of cocaine, can inflame blood vessels and lead to the development of brain aneurysms.

SYMPTOMS OF CEREBRAL ANEURYSM

Most cerebral aneurysms do not show signs until they either become very large or burst. Small, unchanging aneurysms generally will not produce symptoms, whereas a larger aneurysm that is steadily growing may press on tissues and nerves. Symptoms may include pain above and behind the eye; numbness, weakness, or paralysis on one side of the face; dilated pupils; and vision changes. When an aneurysm bleeds, an individual may experience a sudden and extremely severe headache, double vision, nausea, vomiting, stiff neck, and/or loss of consciousness. Patients generally describe the headache as “the worst headache of my life” and it is usually different in severity and intensity from other headaches patients may experience. “Sentinel” or warning headaches may result from an aneurysm that leaks for days to weeks prior to rupture. Only a minority of patients have a sentinel headache prior to aneurysm rupture.
Other signs that a cerebral aneurysm has burst include nausea and vomiting linked with a severe headache, a drooping eyelid, sensitivity to light, and change in mental status or level of awareness. Some individuals may have seizures.

TREATMENT OF CEREBRAL ANEURYSM

Not all cerebral aneurysms burst. Some patients with very small aneurysms may be monitored to detect any growth or onset of symptoms and to ensure destructive treatment of coexisting medical problems and risk factors. Each case is unique, and considerations for treating an unruptured aneurysm include the type, size, and location of the aneurysm; risk of rupture; patient’s age, health, and personal and family medical history; and danger of treatment.

Two surgical options are obtainable for treating cerebral aneurysms, both of which carry some risk to the patient (such as possible damage to other blood vessels, the potential for aneurysm recurrence and rebleeding, and the risk of post-operative stroke).

Micro vascular clipping involves cutting off the flow of blood to the aneurysm. Under anesthesia, a section of the skull is removed and the aneurysm is situated. The neurosurgeon uses a microscope to isolate the blood vessel that feeds the aneurysm and places a small, metal, clothespin-like clip on the aneurysm’s neck, halting its blood supply. The clip remains in the patient and prevents the risk of future bleeding. The piece of the skull is then replaced and the scalp is closed. Clipping has been shown to be highly effective, depending on the location, shape, and size of the aneurysm. In general, aneurysms that are totally clipped surgically do not return.